Device for regulating the feeding of gas turbines



Nov. 30, 1954 J, SZYDLOWSKI DEVICE FOR REGULATING THE FEEDING OF GASTURBINES Filed March 6, 1950 MARKS r51 fwuh United States Patent @fifice2,695,498 Pftented Nov. 30, 1954 temperaturezcforrawhiehvctheznadiulstingremeansnbecomer DEVICE FOR REGULATING THE FEEDING 0F GASTURBDNES'M Thermic: enginessasaat mtesentv-knownazarongenerallycontrolled: ifllroughrzll'eg l iiflfsflhatmiimit itheiradmissioni ofwfueltin accordanceewithitthe: rspeed; ofi notation that is reached. Inthe case of thermic engines,-=;suche=asr2ga$ turbines or: reactions jetaengines; :theresshouldsrbeetaken into account in additionst h necessityofiradjustingethe: speed" of rotatiomzthat; at gtdirectiysoroindirectly: flier-temperature: reachede heapQmhustiomgases; :1 order to prevent the wheels of the turbine that arecrvi air.elements thereof from being rapidly renderedzs'unsemiceabl. r. a

With a Niel/V5.10 .eliminatingstheidrawbacksnhantwouldz result tfromutheabsence of;rsuchtiregulatingrmeans,umw invention hasfortits'irmain-iobjept to-rproyiderforr an :aidjustss. ment of :thetemperatures of ether gasesnbyl r'rneans 2,.ofga temperature responsive:instrument actuating-through SUI Ir. able relays rthezmembersnrthat.adjust rtheizamount ofvfuei fed: to the enginew A further:'ObjfiQt'iOf'IhCIdIIYeHtiOHZ COIISiStS tinzproviding: in:theqcasezofnagas tturbinetonofiameaction jetrenginmt r control means'xofthel'zicharacten:describedau'wherein: thei'i limitationoftthezamountaofrfuel. admitted; 'intoatherthermic: engineis obtainedgraduallwthroughza progressive' adjlistw mentof'thefuel'rinputrssaidtinpptzbeing'redttcech when the; temperaturerisesmzbeyondrtthe selected: value, s-whereas;rit-- iscausedz-tocincreasa' zwhen said predeterminedatempterature is notreachedm This removesgthus ethe drawbackridue to -the fact thatforqsuchipowerrengines;rthe'incorporation bf-meanswom prising aregulator reducing:suddenlytthvamount ofi fuel" fed; .\Vh6fl'ii.h6rtemperature trises beyoncb'a predetermined value; leads :fto-" asudden: reduction :in'? the combustion temperature 2' and in the? powersdevel.oped;. -whicli suddem reduction isgenerallwlnotrallowableHin-practi Thekytemperature responsive-instruments-=- ar located r preferably, in the: case: Where they'areused v'vith a gas turbine or a reactio'ri'jet"turbine streamy-upwardswith ief erence to theiturbine', 'for instancesat the output of 'thecombustion chamber or chamberss- Myinventionha's furthermore foritsobjeqlt thindus trialappl-ic'ationmf =the tfuelfeeding systemdisclosed chiefly in the case of gas turbines, reaction jet turbinespropeller turbinesand more, particularly in the ,case of those gasturbines that are described in my" copending prior specification-rifledllildCf'EtSGl'ifFfNOtlf 126,143 on 6 November 8, 1949 (now abandoned)-for Coaxial Com-., bastion *Products Generator and"Turbine,ithatrinclltdes more :specifically a combustionchambehbf the gtypegdis;closed in my gother copending specification Sfli'aNo 126,141 .filed; onNovember 8, 1949 (now abandoned-M501 a ffCombustion Chamber 'With"DiversmCombustio'n.and- Diluent-Air'Paths The following descriptionmade "with reference to the accompanying drawing will allow a properunderstanding of the practical execution of my invention, the embodimentdisclosed being given by way of a mere exemplification. In said drawing:

Fig. 1 illustrates diagrammatically an arrangement for adjusting theadmission of fuel in a gas turbine by limitation of the amount of fuelin accordance with the tem- 7. perature reached by the gases as theypass out of the combustion chamber of said turbine, said limitationbeing obtained gradually through the progressive adjustment of thethroughput of fuel.

Figs. 2 and 3 are views in its open and closed position W of anarrangement for controlling a switch defining the centrifugalweights-13a 'th 2, 25 i26-zrformingrino parttof fillieeinventionzrsTheringvll its inoperative position :rinibppositiomzto sthezacentrifiugahzchamber:-- forming-; the cylinder.-:;33,.

operative -Fig;= 4 is. armodificatiomoffiigizfl. I l

- The aarrangementiillustrated:" .t lqi'nclndesaa turboe r jean-engine;ha ving pa rcompresson-sd6xnwhichmfeeds nanannulamcombustiorrzchambereilflthousedsinsidelthez casings 1aandsdeliveringstheacombustionzgaaest to .a I turbineie24 housedsinsidevacasing 32am. Theueombustipnxchamben 20.: isurfed Mithafuelsdeliycred by'a :pumptrfiarthattsticks 1th fueleoutmofua'. containrrtha-tilsmotillustratedlthrong a;

: pipe; 4a. Thenpumplaita delivers ethezfiuel :tl1rougir:a:.=pipes 5amrAmalvexfiarfiortadjustingstherpressurerofifuet:deliuereds;iswinscrtedein a- -byepasssilasconnected acitosstirthe pumprSaIsinmrderztowprouidexliquid fiuebrunder*aansadjustahleneons" stantpressure. 5.

In the- :pipe :Saais sinsertedfiac sliderslalves8aaadaptedt to: adjust-the: mount otutuehtdelistered rintor th'efii piper19a i This pipe, 90'feeds:,ttheuemnbiistionnchamber *20 rTiiiszz slidewalve -8a isconnected; momma-manor withtthev movable: ring'; 11a ofua. .centrifiugaltregulator 12am The l N e31regulator-r:Hmaretdriirem into-rotationzthroughrthaspindleiifiarthatris aoonneetedstb; the'rrota-ryrmembersmfthe (turbine through-ta tra'nsmissi ofthe regulatorgzis urged beureturnxspringtfiartoward movement ofzsaidaweiglrtsit Imthetprpee 5a is:ralsoinserted: in vszalve rfiiki controlledr; through, a' hand-operateeyer;rfomprovidingnmanuallyl: theafeedra ofi fuel. .F; There :*isintroducedwinfm theztexhaustp for :the. combu-stiomgasesout:ofatheicotrrbustiomchamhem 20-.contained-.jn the casing 1a;a=-thenmocoupleiflatha't is inserted in series WithwlfhfltzCOibOf1aarelayr llaithrouglrj thezagency. of rtheifleads r22ae In rthecircuitxofztsa'idpleads is inserted;insseriest-withvsaidrthermocouple4aresistance switch .19a actingcas nthermovablefiarmaturez foruthe relayw2la is-.-inserted.-.:-iniseries withglthencircuibiofsa sourcemfaelectric Lennon-@1811 saidweircuit ualsorrincl-uding t inmseriesc: withrthe SOUI'CkzflJfii relays winding: i711: controlling a Maine.37;,equippe d wit-hxarelease springgflri Therswitoh- 19m. allows-currenttospass through-rthe-:windihgflVa oretotben: switched oif. The solenoidactuated valve '3'Zsc0ntrolledr by said winding; 17a.-;is:insentednin:asecond-:ibyspass 336 211502 connected:acrossnthenpumpfiarbetweem th-zpipes-=4a iand: Sam-thenopening 0fasaidrrbypassminto :thex 1beingalpcatedn-onrthe -downfstreamisidca fithetbyz-pas 717'; t

The-:-pressuresoontrollingwalvei6atineludes ai -cylindrical: chambers53awithinnwhich .is mounted a1diaphragmn43': carrying thewaive--.44-%ad-apted; torclosetthedirsti by=pass 7a. ..The'diaphragmmmis =subjec-ted2toztheaaction'fofra spring dl rtheufurther endof .whichvbears against: a move able rpiston 62-slidingrinside;ithe'yehamben233mm! thaiving-w anrareagreaterth-ansthatrof;diaphragnr:43. :Saidrchambe 33 is connected: throughgapipei46 including a i-manna'll adjustable .needlervalve 34;}Wi't'ihfh6pipei-Safiomone hatnd it and on: the othem with {a -piper147 t-inludinga .manuallyfl' adju'stableaneedlei- ;valve :35 .:which; ,cornmrmicateswith i the chamber -10f thetsolenoid- :actuated:valve 37 vTireebyspass-36 rterminatesrithusuinx-seriesewith this.lesssthanatherselectedrtemperature: thezavindingrlhi. of

theh-solenoidwactuatedevalvesfi'k isznottenergized *andrzconsn sequentlyithetval-ve''l' sisclosedzr under the actionrofn'eleasex; spring 27 .Asa-matterxofi factrrthenwindings'tof. theiarelayy 21a is fed by a currentthat is not sufficient for closing the switch 19a by neutralizing theaction of spring 48. The pressure of fuel inside the cylinder 33 is thenequal to the pressure of fuel in the pipe 5a. Said pressure exerts onpiston 32 a force greater than that exerted on diaphragm 43 andconsequently said piston moves toward the left and the spring 31 iscompressed to a maximum and maintains valve 44 in closed position. Inthis case. the adiustment of the flow of fuel to the combustion chambersis performed only through the speed regulator at Sat.

When the temperature of the thermocouple 23a reaches a predeterminedvalueor rises beyond same, the relay 21a is sufiiciently energized forneutralizing the action of spring 48 and the switch 19a forming thearmature of said relay closes. The winding 17a is energized and thevalve 37 opens. Consequently the part of chamber 33 which is connectedto pipes 46 and 47 gradually empties through the valve into the by-pass36 and back into the inlet pipe 4a. This results in a decreasing of thepressure in said part of chamber 33. Piston 32 moves to the right underthe action of'spring 31 which may then expand, permitting valve 44 toopen, under the action of the fluid pressure acting on the left side ofdiaphragm 43. This provides for a gradual lowering of the fuel pressureinside the pipe 5a until the temperature at the thermocouple 23a hasdropped below the temperature selected. As a matter of fact, the fuelpressure is reduced in the pipes 5a and 9a and the amount of fueladmitted per unit of time into the combustion chamber decreasesgradually; the temperature drops also at the output end of said chambersand consequently in the vicinity of the thermocouple. When thetemperature at the thermocouple drops below the selected temperature,the relay 21a is no longer sufficiently energized and the switch 19aopens under the action of spring 48. The valve 37 closes again under theaction of its spring as the winding 17a is no longer energized. Fuelfills again gradually the chamber 33 through the valve 34 and graduallycompresses the spring 31 whereby the pressure in the pipe 5a increasesalso in a gradual manner and allows a progressive increase of the flowof fuel that feeds the'combustion chamber. The combustion temperaturerises then up to the desired value.

From this moment onwards, the precedingly described cyclemay begin overagain. Through an adjustment of the cross-sectional area of pipes 46 and47 left free by the screwing of needle valves 34 and 35, said adjustmentbeing made in accordance with the requirements of the arrangement, it ispossible to reduce the oscillations of the actual combustion temperatureto either side of the selected temperature within comparatively narrowlimits.

In order to obtain extra power in the machine for the taking off of anaircraft on which the turbine 24 forms the power unit and for othersimilar purposes where it is desired to develop a temporary extra-powerthrough a transient increase in the combustion temperature, it ispossible to open the switch 41 in order to insert the resistance in thecircuit of the thermocouple 23a. This operation raises the temperatureat which the relay 21 a becomes operative.

It is possible to associate the operation of said switch 41 with that ofthe hand-operated adjusting valve 30 in order that the switch 41 may beopened only when the valve 30 is in its position of maximum opening asillustrated in Fig. 4. When the lower lever 30a of the handoperatedvalve 30 is shifted to its position of maximum opening, it closes theswitch50 for energizing the electromagnet 51 which in turn opens switch41 normally closed by spring 52. In order to avoid the overload thusobtained from lasting too long a time, the duration of opening of thecontact 41 is limited as illustrated in Figs. 2 and 3 by a time switch.This time switch includes a clockwork having a motor 150 which providesfor a slow rotation of a wheel 101 carrying a number of blades 28 andthat stops automatically as explained hereinafter when one blade hasassumed the position of the preceding blade as occurs when apredetermined time interval t has elapsed. When'it is desired to openthe switch 41, the double arm lever 102 fulcrumed at 29 should beshifted from its position N towards its position S which has for resultto urge towards the left the rod 104 through the agency of the stop 105actuated by the cam 39 forming an arm of lever 102, while the lever 103is simultaneously shifted angularly about its fulcrum 38 by means ofstop and the switch 41 is opened through the agency of a stop 42 carriedby said rod 104. On the one hand, the end 104a of rod 104 is locatedabove the blade 28:: and, on the other hand, switch 151 is closed andthe motor starts and drives Wheel 101 (Fig. 3). The blade 28a of thewheel 101 slowly raises the rod 104 against spring 45 and, after a shorttime that is less than the time t referred to, stop 105 is shiftedsuddenly off the cam 39 of the lever 102 and the end 104a of rod 104escapes from the blade 28a so that rod 104 is returned towards the righthand side of Fig. 3 by the spring 106 whereby the switch 41 is againclosed across the terminals of the resistance 40. Simultaneously switch151 is open under the action of spring 152 and the motor 150 stops, thedisplacement of lever 103 being limited by a stop 153.

When it is desired toopen again the switch 41, it is necessary to returnthe lever into the position N and then to move it back towards S.

Obviously, without widening the scope of my invention, as defined inaccompanying claim, it is possible to modify in various manners theembodiments that have just been disclosed.

More particularly, as concerns the wiring diagram of the arrangement,other arrangements may be resorted to, chiefly as concerns the means foramplifying the current produced by the thermocouple 23a and the time-lagsystem.

What I claim is:

In a heat engine, the provision of an arrangement for controlling theinput of fuel into same including a feed pump and associated feed pipeadapted to deliver fuel into the engine, a first by-pass including anenlarged variable-size chamber having a movable wall, said by-pass'being connected across the feed pump in shunt relationship with the fuelfeed pipe, a second by-pass including a variable-size chamber having amovable wall, said second by-pass being also connected across the pumpin shunt relationship with the feed pipe, the connection of the firstby-pass with the feed pipe section between the feed pump and the enginebeing located on the upstream side of the connection between the secondby-pass and the feed pipe section considered, means for yieldinglyinterengaging the movable walls of the two chambers, a valve carried bythe movable wall of the first chamber and adapted to control the firstby-pass to reduce the pressure of fuel delivered by the pump when thepressure in said second chamber drops and ensuring a reduction inpressure in the first chamber whenever the pressure drops in the secondchamber, a valve adapted to close the second by-pass between the chambertherein and the upstream side of the'feed pipe with reference to thefeed pump, temperature-sensitive means inside the combustion chamber ofthe engine, an electric circuit controlled by said means according tothe temperature assumed thereby, electromagnetic means controlled bysaid circuit and controlling the last mentioned valve to open, when thetemperature considered rises above a predetermined value, the secondby-pass and reduce thereby the pressure in the second chamber andthereby the throughput of fuel through the pipe;

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,336,232 Doran Dec. 7, 1943 2,404,428. Bradbury July 23, 19462,405,888 Holley Aug. 13, 1946 2,422,808 Stokes June 24, 1947 2,432,177Sdille Dec. 9, 1947 2,589,074 Goodwin Mar. 11, 1952]

